DOES THIS APPLY TO THE 2000 Exp. 4.6
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DOES THIS APPLY TO THE 2000 Exp. 4.6
- The aluminum heads on two-valve 4.6L and 5.4L V8s and 6.8L V10s (built in the company's Windsor, Ontario plant, not to be confused with 2005 and up 3-valve heads) have a fatal flaw in the spark plug threads. Being a soft metal, aluminum doesn't have much inherent strength in the first place; it also expands at a different rate than the steel spark plugs threaded into it. Ford put the V10's spark plugs at the bottom of a five inch deep well, and only left enough room to allow for about four threads worth of spark plug engagement in the cylinder head.
- After repeated heat cycling, the spark plug essentially welds itself to the threads, weakening the material and changing the load-bearing center. The end result of this design flaw is that the rear-most spark plugs on the engine's heads tend either randomly shoot out of the block while driving, or get stuck while in the process of removal. When hard steel sticks to soft aluminum, the aluminum will inevitably give way first. The end result is that the head's spark plug threads strip clean out, leaving a smooth hole and no way to re-install the plug.
- Ford covers this engine problem under warranty (Technical Service Bulletin TSB 07-21-2). However, if your engine fails after the warranty expires, you are responsible for the repairs. Ford issued a repair kit called the Lock-and-Stitch that allows the owner to install an aluminum insert where the spark plug threads should be. The kit comes complete with tools, materials and special installation procedures.
- Ford's kit will do the job, but installing aluminum thread inserts in the place of already-failed aluminum threads is a lesson in repeating history. Aftermarket steel-insert kits cost about the same, and are likely to outlive Ford's aluminum band-aids
Any thoughts on this is great... How do I tell if this happens?
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Joined: Aug 2010
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From: High Springs, FL
also if you dont have a good seal on your plugs the compression will come thru and make your wires come off it happened to me........****ing ngk